Tape rule brake mechanism

ABSTRACT

Tape rule brake mechanism consists of a brake device and a positioning member. The rim of the reel on which a measuring tape being coiled around is provided with at least one trammeling block accompanied with a confinement slot. When the brake machanism is actuated, a detent formed at the tip of the brake device drops into the confinement slot and halt the reel rotation by mating with the trammeling block of the reel so as to indirectly stop motion of the tape coiled on the reel. The tape is stably fixed at the position without slipping away by secure engagement of the positioning member with the detent of the brake device. The reset action of the brake device is assisted by the restoring force of a compressed spring.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a tape rule brake mechanism, and more particularly, to a tape rule brake mechanism which halts the rotating reel on which the measuring tape is coiled around instead of directly and forcibly press the moving tape to stop it.

[0003] 2. Description of the Prior Art

[0004] A tape rule brake mechanism is very important to the tape rule user because an inadvertent braking operation may result in cutting the users fingers with the tape edge if the brake force is directly exerted on the rapid moving tape.

[0005] A conventional tape rule brake mechanism consists of a control member and a brake strap. In assembling, the brake mechanism is equipped in an extended space of the tape rule housing. A slide groove is formed in this space for the brake strap to slide along, and the control member is installed on the housing with its one end mating with the end portion of the brake strap so as to push the brake strap downward with the control member and halt the motion of the tape by directly pressing it. However, it should be understood that such a direct pressing action can not be carried out perfectly, the incomplete brake operation by inadequate pressing force causes the tape to slip against large frictional force therefore shortening the lifetime of the tape rule due to quick worn out of the tape by severe abrasion.

[0006] In view of the above mentioned shortcoming inherent to the conventional tape rule brake mechanism, the inventor of the present invention has endeavored to solve this problem with long time study, and finally has come to realization of the present invention.

SUMMARY OF THE INVENTION

[0007] It is the main object of the present invention to provide an elaborate and new tape rule brake mechanism which halts the rotation of the reel instead of directly and forcibly press the rapid moving tape to stope it so as to evade shortening the lifetime of tape rule due to quick worn out of the tape by severe abrasion caused by inadequate pressing force.

[0008] It is another object of the present invention that by holing the rotation of the reel, the measuring tape coiled on it also is able to stop moving at a desired length so as to conduct the survey or measuring work conveniently and efficiently.

[0009] To achieve the above mentioned objects, the brake mechanism equipped on the tape rule housing consists of a brake device and a positioning member. The rim of a reel on which a measuring tape being coiled is provided with at least one trammeling block accompanied with a confinement slot. When the brake mechanism is actuated, a detent formed at the tip of the brake device drops into the confinement slot and halt the reel rotation by mating with the trammeling block of the reel so as to indirectly stop motion of the tape coiled on the reel. The tape is stably fixed at the position without slipping by secure engagement of the positioning member with the brake device detent such that the reel is kept stationary. The braking force of the brake device is released by the restoring force of a compressed spring.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] To enable a further understanding of the innovative and technological content of the invention herein, reference should be made to the detailed description of the invention and the accompanying brief description of the drawings appended below, in which:

[0011]FIGS. 1A and 1B are the exploded illustrative views of the tape rule brake mechanism of the present invention;

[0012]FIG. 2 is a three dimensional perspective view of the tape rule brake mechanism of the present invention; and

[0013]FIG. 3A to FIG. 3C are the detailed drawings illustrating the relative position of all the component parts of the tape rule brake mechanism when it operates.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] Referring to FIGS. 1A, 1B and FIG. 2, the tape rule brake mechanism of the present invention is composed of a tape rule housing 1, a reel 4, a positioning member 3, and a brake device 4.

[0015] The tape rule housing 1 is divided into an upper housing 11 and a lower housing 12. A reel axle 121 is erected from the center portion of the lower housing 12. A first slot 122 and a second slot 123 which is larger than the first slot 122 are formed at the upper rear edge of the lower housing 12. A positioning post 124 is erected on the first slot 122. There is a pivot bearing 125 standing in front of the positioning post 124, and a stopper plate 126 accompanied with a tongue piece 1261 is formed in front of the pivot bearing 125. A fixed pole 127 is standing in front of the second slot 123 and is facing against the pivot bearing 125. Similarly, there are a first slot 111 and a second slot 112 formed successively at the upper housing 11's edge in the position corresponding to the first slot 122 and the second slot 123 of the lower housing 12. A positioning post 113 is extended downward from the fist slot 111 and a hollow column 114 is provided in front of the positioning post 113. When the upper and lower housing 11 and 12 are coupled together, their first slots 111, 122 and second slots 112, 123 are also coupled together so as to form continuous first cavity and second cavity in succession. At this time the pivot bearing 115 of the lower housing 12 is inserted into the hollow column 114 of the upper housing 11 such that the two housings are firmly engaged with each other.

[0016] The reel 4 has a through hole 41 at its center and has at least one trammeling block 42 formed along its rim. One end surface of the trammeling block 42 is formed into approximately a planar portion 421 while the other end surface an arcuate portion 422 such that a confinement slot 43 is formed therebetween. The reel 4, with a measuring tape coiled thereon, is inserted into the axle 121 with its central through hole 41, so as to rotate about the axle 121 in the tape rule housing 1 for stretching out or retrieving back the measuring tape 5.

[0017] The positioning member 3 is provided with a push button 31 at its top surface thereof on which several friction stripes 311 are formed. The bottom of the push button 31 is formed into a notch 32, and an eye hole 33 is formed under the notch 33, the end part of the positioning member 3 is formed into a hook arm 34 with two claws 341, 342 provided at its tip and rear end respectively.

[0018] The brake device 2 is made hollow and a push plate 21 is provided at its top portion, and a via hole 22 is formed at its middle portion. The bottom portion thereof is bifurcated into a pair of detents 23. One end of the detent 23 is formed into a chamfered edge 231, while the other end thereof is formed into a detention block 232. An open trough 24 with a stopper strap 25 is provided at a side of the brake device 2.

[0019] In assembling, the eye hole 33 of the positioning ember 3 is fitted over the pivot bearing 125 of the lower housing 122 so that the positioning member 3 is displaceable forward and backward with respect to the pivot bearing 125, while the notch 32 under the push button 31 can be hinged to the positioning post 124 so as to emerge the push button 31 out of the first slots 111, 112 of the upper and the lower housings, while the hook arm 34 at the bottom portion thereof is detained by the stopper plate 126 of the lower housing 12. By doing so the tip claw 342 of the hook arm 34 is engaged with the tongue piece 1261 of the stopper plate 126 thereby the positioning member 3 is fixed thereat. On the other hand, the brake device 2 is up and down movably assembled by fitting its central via hole 22 over the fixed pole 127 of the lower housing 12. At this time the push plate 21 is emerged out of the second slots 112, 123 of the upper and the lower housings 11, 12, and the stopper strap 25 of the brake device 2 is facing against the positioning member 3. A compressed spring 6 is provided for the brake device 2 with its one end 61 secured to the side surface of the fixed pole 127, while the other end 62 thereof to the upper inner wall surface of the brake device 2 thereby completing the assembly of the brake mechanism on the tape rule.

[0020] In order to understand how the tape rule brake mechanism of the present invention works, reference should be made to FIGS. 3A through 3C wherein the positional relationship of all the component parts of the brake mechanism is shown. The push plate 21 of the brake device 2 is pushed down to initiate the brake operation. At this time the bifurcated detents 23 bring their chamfered edges 231 into the confinement slots 43 of the reel 4 along the arcuate surfaces 422 of the trammeling blocks 42 so that the reel 4 is blocked and can not rotate to stretch or retrieve the tape 5. For firmly fixing both the reel 4 and the tape 5 at this position, the push button 31 is pushed to advance the positioning member 3 one step forward so as to release the tip claw 342 of the hook arm 34 from the tongue piece 1261 and bring the rear claw 341 into engagement with the stopper strap 25 of the brake device 2. At this moment, the compressed spring 6 installed in the brake device 2 is in a compressed state to store the restoring energy. In releasing the reel 4 from the detained stage, the push button 31 is reset to disengage the rear claw 341 from the stopper strap 25 of the brake device 2 thereby the brake device 2 is brought back to its initial position by restoring force of the compressed spring 6.

[0021] It emerges from the above description that the tape rule brake mechanism of the present invention has several noteworthy merits, namely:

[0022] 1. The brake mechanism operates to halt the reel rotation instead of directly forcing the tape to stop so that damage to the tape due to abrasion or accident of scratching the user's fingers never happens.

[0023] 2. Rapid positioning the tape at the desired position facilitates the user to perform measuring work.

[0024] Although the preferred embodiment of the present invention has been educidated for illustrative purposes, those skilled in the arts will appreciate that various modifications, additions and substitutions are possible without departing from the scope or the spirit of the invention as disclosed in the appended claims. 

What is claimed is:
 1. A tape rule brake mechanism comprising: a tape rule housing divided into an upper housing and a lower housing, a first and a second slots being formed in succession at the upper rear edge of said lower housing, a positioning post being erected on said first slot, and a pivot bearing being standing in front of said positioning post, a stopper plate accompanied with a tongue piece being formed in front of said pivot bearing, a fixed pole being standing in front of said second slot; similarly, another first and another second slots being formed in succession along said upper housing's edge, a positioning post being extended downward from said upper first slot, and a hollow column being provided in front of said positioning post, when said upper and said lower housing being coupled together, their first slots and second slots being also coupled together so as to form continuous first and second cavities, at this time, said pivot bearing being inserted into said hollow column of said upper housing such that said two housings being able to engage firmly with each other. a reel for coiling an a measuring tape being provided at least one trammeling block formed along its rim thereof, each trammeling block being provided with a confinement slot, said reel being accommodated in said tape rule housing for extending and retrieving said tape by rotation; A positioning member being provided with a push button at its top surface thereof, the bottom of said push button being formed into a notch, and an eye hole being formed under said notch, the end part of said positioning member being formed into a hook arm with two claws at its tip and rear end, when said eye hole of said positioning member is fitted over said pivot bearing, said notch under said push button can be hinged to said positioning post of said tape rule housing so that said push button is emerged out of said combined first slot of said upper and said lower housings, while said hook arm at the bottom of said positioning member is detained by said stopper plate with its tongue piece engaging with the top claw of said hook arm; a hollow braking device being provided with a push plate at its top portion thereof, and a via hole being formed at its middle portion thereof, the bottom portion thereof being bifurcated into a pair of detents, an open trough with a stopper strap being provided at one side of said brake device; for assembling said brake device on said tape rule housing the central via hole of said brake device is fitted over said fixed pole of said lower housing so as to emerge said push plate out of said combined second slot of said upper and said lower housings, and face said stopper strap against said positioning member and a compressed spring whose one end secured to the side surface of said fixed pole, while the other end thereof the upper inner wall surface of side brake device is provided for said brake device to serve its restoring force for the brake device to reset.
 2. The tape rule brake mechanism of claim 1, wherein a reel axle is erected from the center portion of said lower housing, said reel is provided with a central through hole to fit over said axle such that said reel is rotatable about said axle in said tape rule housing to stretch or retrieve the measuring tape.
 3. The tape rule brake mechanism of claim 1, wherein said combined second slot formed by coupling said upper and lower housings is larger than said first one.
 4. The tape rule brake mechanism of claim 1, wherein said detents of said brake device is able to be engaged with the trammeling block of said reel so as to detain the rotation of said reel together with said measuring tape coiled thereon, and said brake device is positioned by engaging said tip claw of the hook arm with said stopper strap of the brake device and compressing said compressed spring in said brake device.
 5. The tape rule brake mechanism of claim 1, wherein said positioning member is displaceable forward and backward with respect to said pivot when being fitted thereof.
 6. The tape rule brake mechanism of claim 1, wherein said push button of the positioning member is provided with several friction stripes on its top surface thereof so as to prevent slipping when being operated.
 7. The tape rule brake mechanism of claim 1, wherein said brake device is movable up and down by fitting its central via hole over the fixed pole of said lower housing.
 8. The tape rule brake mechanism of claim 4, wherein one end surface of the trammeling block provided along the rim of said reel is formed into approximately a planar portion while the other end surface an arcuate portion, besides, one end of each bifurcated detent is formed into a chamfered edge, while the other end thereof is formed into a detention block, with this structure, each of said detents brings its chamfered edge into the confinement slot of said reel along said arcuate surface of said trammeling block thereby reel is blocked and can not rotate to stretch or retrieve said measuring tape.
 9. The tape rule brake mechanism of claim 4, wherein when the rear claw of said hook arm is disengaged from the stopper strap of said brake device, said brake device is reset to its initial position by the restoring force of said compressed spring. 